The Journal of Neuroscience, December 15, 2002, 22(24):10958-10965
Modulation by Central and Basolateral Amygdalar Nuclei of
Dopaminergic Correlates of Feeding to Satiety in the Rat Nucleus
Accumbens and Medial Prefrontal Cortex
Soyon
Ahn and
Anthony G.
Phillips
Department of Psychiatry and the Brain Research Centre, University
of British Columbia, Vancouver, Canada V6T 2A1
Current studies raise the possibility that subregions within
the amygdala may interact with the mesocorticolimbic dopamine (DA)
system to subserve specific psychological processes underlying food
reward. The present study compared the effect of reversible inactivation of the central nucleus (CeN) versus the basolateral amygdala (BLA) on DA efflux in the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) in hungry rats that were tested in a food-devaluation procedure. During DA microdialysis experiments, lidocaine, a sodium channel blocker, was delivered via reverse dialysis
into the CeN or BLA while rats were given two consecutive meals of
Froot Loops. Loss of CeN function impaired the development of
satiety during an initial meal and, consequently, diminished the effect
of devaluation by satiety on intake of the same food during a second
meal. Inactivation of the CeN was also associated with decreased basal
levels of DA efflux in the NAc before food intake and attenuated
increases in DA efflux related to anticipatory and consummatory aspects
of feeding in both the NAc and mPFC. In contrast, inactivation of the
BLA did not affect feeding behavior or DA efflux. Overall, these
findings indicate that the CeN and BLA independently modulate DA
transmission in both terminal regions. It is proposed that interaction
between the CeN and mesocorticolimbic DA activity may be a mechanism by
which hunger and satiety signals influence the value of food reward, or
alternatively, a mechanism by which memory for a recently consumed food
regulates food intake.
Key words:
microdialysis; reverse dialysis; lidocaine; reversible
inactivation; incentive devaluation; food reward
Copyright © 2002 Society for Neuroscience 0270-6474/02/222410958-08$05.00/0
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